A replicated, paired sites study in 2002–2003 on 65 pairs of farms in England, UK (Fuller et al 2005) found that organic farms had higher bat activity and a greater number of bat species than conventional farms. Significantly more bat passes and more bat species were recorded on organic farms than conventional farms (abundance index 6–75% higher on organic farms; species density 8–65% higher). Organic farms with >30 ha of arable land were paired with nearby conventional farms matched by crop type and cropping season. Habitat data collected across all 130 farms showed that organic farms had a higher density of hedgerows, a greater proportion of grassland than crops, smaller fields and wider, taller hedgerows with fewer gaps than conventional farms. Each of 130 farms was surveyed using bat detectors along a 3 km triangular transect in June–August in 2002 and 2003.